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The presence of an aromatic additive has been seen to enhance, often significantly, the enantioselectivity and yield in asymmetric organocatalysis. Considering their success across a dizzying range of organocatalysts and organic transformations, it would seem unlikely that a common principle exists for their functioning. However, the current investigations with DFT suggest a general principle: the phenolic additive sandwiches itself, through hydrogen bonding and π⋅⋅⋅π stacking, between the organocatalyst coordinated electrophile and nucleophile. This is seen for a wide range of experimentally reported systems. That such complex formation leads to enhanced stereoselectivity is then demonstrated for two cases: the cinchona alkaloid complex (BzCPD), catalysing thiocyanation (2‐naphthol additive employed), as well as for L‐pipecolicacid catalysing the asymmetric nitroaldol reaction with a range of nitro‐substituted phenol additives. These findings, indicating that dual catalysis takes place when phenolic additives are employed, are likely to have a significant impact on the field of asymmetric organocatalysis. [ABSTRACT FROM AUTHOR]

The great success of asymmetric organocatalysis has made it one of the most important advancements made in chemistry in the past two decades. A significant achievement in this context is the asymmetric organocatalysis of the thiocyanation reaction. In the current study, computational studies with density functional theory have been done in order to understand an interesting experimental finding: the reversal of enantioselectivity from R to S when the electrophile is changed from β‐keto ester to oxindole for the thiocyanation reaction with the cinchona alkaloid complex catalyst. The calculations reveal an unusual fact – the principal reason for the reversal is the presence of the C−H⋅⋅⋅S noncovalent interaction, which is present only in the major transition states in each of the two nucleophile cases. Only recently has it been realized that the supposedly weak C−H⋅⋅⋅S noncovalent interaction has the properties of a hydrogen bond, and the fact that this interaction is the cause of enantioselectivity has relevance, because of the large number of asymmetric transformations involving the sulphur heteroatom. [ABSTRACT FROM AUTHOR]

A new mechanism has been proposed for the hydroboration of aldehydes by germylene and stannylene complexes, with the aid of the hydroborating agent, pinacolborane (HBpin). This new mechanism is demonstrated with computational studies with density functional theory (DFT), not only for existing systems, but also for newly designed germylene and stannylene systems. [Display omitted] The chemistry of low valent main group compounds has grown as an alternative to the chemistry of less abundant and less green transition metal complexes. It has been found that low valent compounds such as carbenes, silylenes, stannylenes and germylenes are efficient for activating small molecules and for catalysis. However, the reaction mechanism and the factors that affect the rate of reaction are not completely understood. In this computational investigation with density functional theory (DFT), we investigate and demonstrate the efficiency of a new mechanism for the hydroboration of aldehydes by germylenes and stannylenes, in the presence of the common hydroborating agent, pinacolborane, HBpin. This mechanism involves an HBpin molecule as an additional catalyst that cooperates with the germylene or stannylene catalyst to efficiently carry out the hydroboration. This mechanism is first demonstrated to work for experimentally reported systems, and then shown to be efficient for newly proposed germylene and stannylene systems. These new systems are α-Borylamido-germylene ((2,6- i Pr 2 C 6 H 3 NBCy 2) 2 Ge(II)) and α-Borylamido-stannylene((2,6- i Pr 2 C 6 H 3 NBCy 2) 2 Sn(II)). These new insights will help researchers look into low valent germylene and stannylene chemistry from a new perspective. [ABSTRACT FROM AUTHOR]

The combination of 6-SIDipp·AlH3 (1) and 5-IDipp resulted in the ring expansion of 6-NHC, while the five-membered NHC remained unchanged, which was subsequently explained by DFT studies. Besides, the substitution chemistry of 1 was also studied with TMSOTf and I2, which gave rise to the substitution of a hydride by triflate or iodide ligands. [ABSTRACT FROM AUTHOR]

A series of 21 sulfoester and sulfonamide derivatives comprising two aromatic rings was synthesized to investigate the effect of the presence of either electron-donating (ED) or electron-withdrawing (EW) groups on the intramolecular π-stacking assembly. The positioning of ED or EW moieties was carried out directly on one of the aromatic rings linked to the sulfonyl or sulfonamide moieties. In contrast, the other aromatic ring (phenyl or pyridine) was connected by a –CH2–CH2– spacer with the sulfonyl or sulfonamide moiety. The purpose of having an ethyl spacer between the two aromatic rings was to achieve conformational flexibility, facilitating the intramolecular π-stacking assembly between the two aromatic rings. The use of sulfoester/sulfonamide groups allowed more conformational flexibility to attain desired orientations in solids with the interplay of the hydrogen-bonding interactions. Between the two functional groups, sulfonamides offered a more hydrogen-rich environment due to the amine moiety and may exhibit higher H-bonding propensity than the sulfoester moiety. The central idea here was to study the interplay between the hydrogen-bonding and π⋯π interactions. The substituent groups chosen were categorized as strong electron-withdrawing (–CF3 and –CN), weak electron-withdrawing (–Cl and –Br), neutral (–H), and good electron-donating (–CH3 and –OCH3) groups. Crystal structure analysis revealed the syn conformation for all the derivatives, enabling intramolecular π⋯π interactions between the two aromatic rings, whereas in the sulfonamide derivatives, the molecule takes either midway or anti conformations, except for one pyridine sulfonamide derivative, which showed the syn orientation but lacked intramolecular π-stacking interactions. The absence of any conventional H-bond forming functional groups in the sulfoester derivatives may have resulted in the syn geometry facilitated by intramolecular π-stacking interactions. Conversely, H-bond-forming functional groups in the sulfonamide derivatives could have prevented the syn conformation. The conformational analysis carried out employing density functional theory (DFT) calculations confirmed the higher stability of the syn conformation over the midway and anti orientations. [ABSTRACT FROM AUTHOR]

The reaction of a nickel(II) chloride complex containing a tridentate β‐diketiminato ligand with a picolyl group [2,6‐iPr2‐C6H3NC(Me)CHC(Me)NH(CH2py)]Ni(II)Cl (1)] with KSi(SiMe3)3 conveniently afforded a nickel(I) radical with a T‐shaped geometry (2). The compound's metalloradical nature was confirmed through electron paramagnetic resonance (EPR) studies and its reaction with TEMPO, resulting in the formation of a highly unusual three‐membered nickeloxaziridine complex (3). When reacted with disulfide and diselenide, the S−S and Se−Se bonds were cleaved, and a coupled product was formed through carbon atom of the pyridine‐imine group. The nickel(I) radical activates dihydrogen at room temperature and atmospheric pressure to give the monomeric nickel hydride. [ABSTRACT FROM AUTHOR]

Disilenes with differently coordinated silicon atoms are not known. Here, we have shown the high yield synthesis of a range of disilenes (2–4 and 6) upon reaction of a hypersilyl silylene PhC(NtBu)2SiSi(SiMe3)3 (1) with aliphatic chlorophosphines. The most striking characteristic of these disilenes is the presence of two differently coordinated Si atoms (one is three‐coordinated, the other four‐coordinated). The analogous reaction with Ph2PCl did not afford the desired disilene, but, surprisingly, led to the first tetraphosphinosilane (8). DFT calculations were performed to understand the bonding in disilenes and differences in reactivity of the complexes. [ABSTRACT FROM AUTHOR]

Disilenes with differently coordinated silicon atoms are not known. Here, we have shown the high yield synthesis of a range of disilenes (2–4 and 6) upon reaction of a hypersilyl silylene PhC(NtBu)2SiSi(SiMe3)3 (1) with aliphatic chlorophosphines. The most striking characteristic of these disilenes is the presence of two differently coordinated Si atoms (one is three‐coordinated, the other four‐coordinated). The analogous reaction with Ph2PCl did not afford the desired disilene, but, surprisingly, led to the first tetraphosphinosilane (8). DFT calculations were performed to understand the bonding in disilenes and differences in reactivity of the complexes. [ABSTRACT FROM AUTHOR]

Squaraine dyes possess sharp far‐red active transition with high extinction coefficient and form aggregates on TiO2 surface. Aggregation of dyes on TiO2 has been considered as a detrimental factor for DSSC device performance, which can be controlled by appending alkyl groups to the dye structures. Hence by integrating alkylated (alkyl groups with both in‐plane and out‐of‐plane) aryl group with indoline moiety to make it compatible with other electrolytes and for controlling the dye‐aggregation, a series of squaraine acceptor‐based dyes SQA4‐6 have been designed and synthesized. SQA4‐6 dyes showed absorption between 642 and 653 nm (λmax), photophysical and electrochemical studies indicated that the HOMO energy levels of this sets of dyes are well aligned with the potentials of I−/I3−$$ {\mathrm{I}}_3^{-} $$ and [Co(bpy)3]2+/3+ redox shuttles for better dye regeneration process. DSSC device efficiency of 3% has been achieved for SQA5 dye with iodolyte (I−/I3−$$ {\mathrm{I}}_3^{-} $$) electrolyte in the presence of 0.3 mM of chenodeoxycholic acid (CDCA). The IPCE profile of DSSC device fabricated with SQA4‐6 dyes indicated the contribution of aggregated structures for the photocurrent generation. [ABSTRACT FROM AUTHOR]

In the last decade, magnesium complexes have emerged as a viable alternative to transition‐metal catalysts for the hydrofunctionalization of unsaturated bonds. However, their potential for advanced catalytic reactions has not been thoroughly investigated. To address this gap, we have developed a novel magnesium amide compound (3) using a PNP framework that is both bulky and flexible. Our research demonstrates that compound 3 can effectively catalyze the synthesis of biologically significant oxazolidinone derivatives. This synthesis involves a tandem reaction of hydroalkoxylation and cyclohydroamination of isocyanate using propargyl alcohol. Furthermore, we conducted comprehensive theoretical calculations to gain insights into the reaction mechanism. It is important to note that these types of transformations have not been reported for magnesium and would significantly enhance the catalytic portfolio of the 7th most abundant element. [ABSTRACT FROM AUTHOR]

Treatment of trans-[Ir(H)(N)2(iPr)4(POCOP)(DMAP)][BAr4f] (2) with H2 (1 bar) under ambient conditions (298 K) results in the formation of a trans-[Ir(H)(η2-H2)(iPr)4(POCOP)(DMAP)][BAr4f] (3) complex. Complex 3 exhibits H-atom site exchange between the bound H2 and the hydride ligands which are mutually trans to one another. A plausible mechanism of this exchange involves metal–ligand cooperativity as studied by computations. [ABSTRACT FROM AUTHOR]

A 12‐membered zwitterionic tetrastanna(II) cycle 1 having a crown ether‐like topology has been isolated from the deprotonation of 1,1′‐methylenediimidazole (B) with two equivalents of Sn[N(SiMe3)2]2 (A). The solid‐state structure and NMR analysis confirms the tetrastanna(II) cycle 1 to be comprised of two stannate(II) and two stannyliumylidene ion pairs in alternating positions of the heterocycle. Computational analysis shows greater nucleophilicity at the proximally located stannate(II) centers. Nonetheless, the tetrastanna(II) cycle 1 remains poorly reactive due to engagement of SnII lone pair electrons in intramolecular donor‐acceptor interactions. Simple deprotonation reaction between Sn[N(SiMe3)2]2 (A) and N‐(diisopropylphenyl)imidazole (C) in equimolar ratio has led to a stannylene 2, involving the formation of a Sn−C covalent bond with the anionic imidazol‐2‐yl carbon center along with the release of NH(SiMe3)2. Compound 2 exists as a dimer, where the unsubstituted ring nitrogen atom coordinated intermolecularly to the other stannylene center. [ABSTRACT FROM AUTHOR]

In this work, 5‐SIDipp [SIDipp=1,3‐bis(2,6‐diisopropylphenyl)‐imidazolin‐2‐ylidene] (1) derived Chichibabin's hydrocarbon with an octafluorobiphenylene spacer (3) has been reported. The addition of two equivalents of 5‐SIDipp with decafluorobiphenyl in presence of BF3 gives the double C−F bond activated imidazolium salt with two tetrafluoroborate anions, 2. Further reduction of 2 gives the fluorine substituted 5‐SIDipp based Chichibabin's hydrocarbon, 3. Quantum chemical calculations suggested a singlet state of 3 with a singlet–triplet energy gap (ΔES‐T) of 3.7 kcal mol−1, which is substantially lower with respect to the hydrogen substituted NHC‐based Chichibabin's hydrocarbons (10.7 kcal mol−1, B3LYP). As a result, the diradical character (y) of 3 (y=0.62) is also noticeably higher than the hydrogen substituted CHs (y=0.41–0.43). The ▵ES‐T was found to be higher in CASSCF (22.24 kcal mol−1) and CASPT2 (11.17 kcal mol−1) for 3 and the diradical character (d) is 44.6 %. [ABSTRACT FROM AUTHOR]

This paper describes the rare use of a 6‐membered saturated N‐heterocyclic carbene (NHC) known as 1,3‐di(2,6‐diisopropylphenyl) tetrahydropyrimidine‐2‐ylidene (abbreviated as 6‐SIDipp) as a ligand in zinc chemistry. We report on the investigation of the reactions between 6‐SIDipp and ZnX2, which resulted in a range of new monomeric 6‐SIDipp⋅ZnX2 complexes (X=Et (1), Cl (2), Br (3), and I (4)). We also prepared a new NHC zinc complex where the two substituents of the zinc atom are different, 6‐SIDipp⋅Zn(Et)Br (7) through the reaction of the proligand [6‐SIDippH]Br with ZnEt2. We have observed that the reactions of complex 1 with sulfur and HBpin led to the removal of the ZnEt2 moiety, resulting in the formation of a C=S double bond and a B−H activation product, respectively. Lastly, the reaction of 1 with five‐membered NHCs led to the exchange of carbene and the formation of either 5‐IDipp⋅ZnEt2 (8) or 5‐SIDipp⋅ZnEt2 (9). [ABSTRACT FROM AUTHOR]

Rivaroxaban (RXB) is a direct factor Xa inhibitor used for the treatment of deep vein thrombosis (DVT, a blood clot in the leg) and pulmonary embolism (PE, a blood clot in the lung) and to prevent blood clots in atrial fibrillation following hip or knee surgery. However, RXB suffers from poor solubility that hinders its broader application. Although its cocrystals are reported for solubility enhancement, the methodology used to prepare multi-component crystals is complex. Also, it uses hazardous solvents to develop cocrystals. We have prepared eutectics of RXB with caffeic acid (CAA), coumaric acid (CA), fumaric acid (FA), succinic acid (SA), mandelic acid (MA) and trimesic acid (TA) and analyzed them using hot stage microscopy (HSM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and fourier transform infrared spectroscopy (FTIR) techniques. The saturation solubility and dissolution rate profiles were also obtained to investigate the effect of eutectics on these parameters. Amongst all the coformers tested, coformers CAA, CA, and FA showed significant enhancement in the solubility of RXB. The powder dissolution rate of the eutectics showed considerable enhancement compared to that of RXB. In vivo pharmacokinetic study was carried out for RXB–CAA, RXB–CA and RXB–FA in rats and compared with RXB, which showed 1.5 and 1.4 times enhancement in relative bioavailability for RXB–CAA and RXB–CA, respectively. Stability studies were carried out as per ICH guidelines for all the eutectics, which revealed excellent stability over six months under accelerated (40 °C and 75%) conditions and twelve months under long-term (30 °C and 60% RH) conditions. The DFT studies carried out using the B3LYP/TZVP level of theory revealed higher Gibbs free interaction energy (ΔGint) for homosynthons (drug⋯drug and coformer⋯coformer) than heterosynthons (drug⋯coformer). [ABSTRACT FROM AUTHOR]

A series of alkyl‐group‐functionalized, aniline‐ and indoline‐donor‐based, unsymmetrical visible‐light‐active squaraine dyes, AM1‐3, were designed and synthesized. Dye‐sensitized solar cell (DSSC) devices were fabricated with both I−/I3− and [Cu(tmby)2]+/2+ electrolytes. DSSC devices sensitized with the AM1 and AM2 dyes showed relatively high‐power conversion efficiency of 7.44 % and 7.22 %, respectively with I−/I3− in the absence of chenodeoxycholic acid (CDCA) than those of the AM3 dye (5.41 %). The [Cu(tmby)2]+/2+ electrolyte along with poly(3,4‐ethylenedioxythiophene) (PEDOT) as cathode material showed excellent open‐circuit potentials (VOC) of 1030, 1025, and 1001 mV with the DSSC efficiency of 8.05 %, 7.96 %, and 5.84 %, respectively, for the AM1, AM2, and AM3 dyes in the absence of CDCA. Here, the AM1 dye exhibited the maximum DSSC efficiency of 8.05 % and VOC of 1030 mV, which is the highest obtained efficiency and VOC for the visible‐light active zwitterionic unsymmetrical‐squaraine dye with copper‐based electrolyte. [ABSTRACT FROM AUTHOR]

This work describes a transition metal-free methodology involving an efficient and controlled reduction of isocyanates to only formamide derivatives using pinacolborane (HBpin) as the hydrogenating agent and a bis(phosphino)carbazole ligand stabilized magnesium methyl complex (1) as the catalyst. A large number of substrates undergo selective hydroboration and give exclusively N-boryl formamides. [ABSTRACT FROM AUTHOR]

The reaction of PhC(NtBu)2SiSi(SiMe3)3 (1) with Me3SiCH2Cl afforded an unsymmetrical sp2–sp3 disilene, 2, with concomitant elimination of Me3SiCl. The analogous reaction with PhC(NtBu)2SiCl resulted in the oxidative addition of the C–Cl bond at the Si(II) atom (3). The reactions of 2 with sulfur and selenium led to compounds with Si＝E (E＝S (4) and Se (5)) double bonds. Tellurium reacted differently with 2 and furnished a zwitterionic compound, 6. [ABSTRACT FROM AUTHOR]

Herein, we report two 2,2′-pyridylpyrrolide (PyPyrH) ligand supported magnesium complexes (1 and 2), which demonstrate bright luminescence with a quantum yield of 22% and 14% in the solid state, respectively. Theoretical calculations reveal that their emissive properties originate from the intra- and inter-ligand charge transfer. [ABSTRACT FROM AUTHOR]

The NHC·borane chemistry has been majorly restricted to imidazol-2-ylidene classes of carbenes. In our previous communication, we reported the synthesis of 6-SIDipp·BH3 [6-SIDipp = 1,3-di(2,6-diisopropylphenyl) tetrahydropyrimidine-2-ylidene] and its electrophilic substitution reaction with iodine. Here, we have shown selective bromination of a 6-SIDipp stabilized sp3 B–H bond. Treatment of 1.2 equivalents of N-bromosuccinamide with 6-SIDipp·BH3 gives a mixture of mono- and disubstituted products 6-SIDipp·BH2Br (1) and 6-SIDipp·BHBr2 (2). However, the reactions with alkyl bromides or carbon tetrabromide resulted in 6-SIDipp·BH2Br (1) selectively. Exploration of the chemistry of 6-SIDipp with BHCl2 and 9-BBN (9-borabicyclo[3.3.1]nonane) led to mono-6-SIDipp adducts 3 and 6a. Furthermore, 6a undergoes ring expansion to afford a seven-membered product, 6b, under mild conditions. Unlike BHCl2 or 9-BBN, the B–H bond of HBpin undergoes oxidative addition upon reaction with 6-SIDipp, epitomizing the first example (7) of a B–H bond insertion at NHCs. The analogous reactivity with HBcat led to a tetrahydropyrimidinium salt with B(cat)2 as a counteranion (8). [ABSTRACT FROM AUTHOR]

• Oxidative addition of dihydrogen molecule has been studied using four coordinate iridium pincer [Ir(iPr)4(POCOP)(PPh 3)] complex. • A complete isomerization of oxidatively added kinetic product, cis-[Ir(H) 2 (iPr)4(POCOP)(PPh 3)] to thermodynamically stable product, trans-[Ir(H) 2 (iPr)4(POCOP)(PPh 3)] complex was noted at 298 K. • A kinetics and mechanistic studies of cis-trans isomerization was discussed and further investigated computationally. • Protonation of trans-[Ir(H) 2 (iPr)4(POCOP)(PPh 3)] complex resulted in a novel trans-dihydrogen hydride, trans-[Ir(H)(η2–H 2)(iPr)4(POCOP)(PPh 3)]+complex at 183 K. • Cis-[Ir(H) 2 (iPr)4(POCOP)(PPh 3)] complex is found to be a catalytically active species towards the hydrogenation of ethylene at ambient conditions. Reaction of a four coordinate, 16-electron Ir complex, [Ir(iPr)4(POCOP)(PPh 3)] (4) ((iPr)4(POCOP = 2,6-bis(di-isopropyl phosphinito)benzene, κ 3-C 6 H 3 -1,3-[OP(iPr) 2 ] 2), with H 2 resulted in an oxidative addition product, cis-dihydride complex, cis-[Ir(H) 2 (iPr)4(POCOP)(PPh 3)] (cis-5) presumably via the intermediacy of a sigma complex, [Ir(η2-H 2)(iPr)4(POCOP)(PPh 3)]. The cis-dihydride complex completely isomerizes to the trans-dihydride complex trans-[Ir(H) 2 (iPr)4(POCOP)(PPh 3)] (trans-5) under ambient conditions in about 3 h. It was found that the steric and electronic features on the iridium center have significant influence on the approach of H 2 onto the metal center followed by oxidative addition and isomerization. The isomerization process was studied in detail and all the mechanistic aspects have been elucidated using a combination of both experimental work and computation. The cis-dihydride complex isomerizes to the trans-dihydride by compensating the trans influence of the strongly trans-directing hydride ligand. A mechanism involving the exchange of the position of PPh 3 with a hydride ligand cis to itself via PPh 3 dissociation and re-coordination thereby resulting in the formation of the trans-dihydride complex, has been proposed for the isomerization. The cis-dihydride was found to be a highly active catalyst for hydrogenation of ethylene. A competing reactivity study of cis-dihydride between isomerization versus insertion of C 2 H 4 into the Ir—H bond, was studied experimentally and computationally. [Display omitted] [ABSTRACT FROM AUTHOR]

We report the synthesis of a calcium complex (2) bearing a tetradentate monoanionic ligand with a diaminoethane core and phenolate and pyridine peripheral donors. Single crystal X‐ray studies on 2 revealed that LiI was also co‐crystallized, leading to a four‐membered ring with four different elements. 2 was found to be an efficient catalyst for the cyclotrimerization of a variety of aromatic isocyanates under mild conditions. [ABSTRACT FROM AUTHOR]

Herein, we have undertaken the synthesis and investigated the reactivity of a 6-membered saturated NHC borane adduct (1). Direct electrophilic halogenation of 1 with a stoichiometric amount of I2 led to NHC boryl iodides, 6-SIDipp·BH2I (2) and 6-SIDipp·BHI2 (3), which were further reacted with various nucleophiles to give novel 6-SIDipp based mono and disubstituted boranes with OTf (4 and 6) or ONO2 (5 and 7) functional groups. The addition of Br2/H2O to 1 smoothly results in a dihydroxyborenium cation (8). [ABSTRACT FROM AUTHOR]

Although hybrid bidentate ligands are known to yield highly enantioselective products in asymmetric hydrogenation (AH), synthesis of these ligands is an arduous process. Herein, a one pot, atom‐economic synthesis of a hybrid phosphine‐phosphite (L1) is reported. After understanding the reactivity difference between an O‐nucleophile versus C‐nucleophile, one pot synthesis of Senphos (L1) was achieved (72 %). When L1 was treated with [Rh], 31P NMR revealed bidentate coordination to Rh. Senphos, in the presence of rhodium, catalyzes the AH of Methyl‐2‐acetamido‐3‐phenylacrylate and discloses an unprecedented turn over frequency of 2289, along with excellent enantio‐selectivity (92 %). The generality is demonstrated by hydrogenating an array of alkenes. The AH operates under mild conditions of 1–2 bar H2 pressure, at room temperature. The practical relevance of L1 is demonstrated by scaling‐up the reaction to 1 g and by synthesizing DOPA, a drug widely employed for the treatment of Parkinson's disease. Computational insights indicate that the R isomer is preferred by 3.8 kcal/mol over the S isomer. [ABSTRACT FROM AUTHOR]

In contrast to the recent reports on catalytic hydroboration of amides to amines with pinacolborane (HBpin), a simple catalyst-free and solvent-free method for the hydroboration of a variety of amides has been realized. To get the mechanistic insights, DFT calculations have been performed. [ABSTRACT FROM AUTHOR]

• The crystal is monoclinic for compound 1, with space group C2/c. • The structures were confirmed by spectroscopic studies. • The computational data gave the ionization energy (IE) and electron affinity (EA) values for the molecule as 4.025 and 2.110 eV, respectively. • Docking calculations indicate binding interactions with both protein (aromatase and fibroblast growth factor receptor) targets. Schiff base, 4-(((1 E ,2 Z)-2‑chloro-3-phenylallylidene)amino)-1,5-dimethyl-2-phenyl-1,2-dihydro-3 H -pyrazol-3-one (1) was synthesized by condensation reaction of 4-aminoantipyrine and α-chlorocinnamaldehyde. The compound was characterized using Fourier-transform infrared spectroscopy (FT-IR), ultraviolet (UV)-visible spectroscopy, proton and carbon nuclear magnetic resonance spectroscopy (1H/13C NMR) and single-crystal X-ray diffraction analysis (SC-XRD). Density functional theory (DFT) was used to compute molecular parameters and also compared them with experimental data. The X-ray diffraction data revealed that the compound crystallizes as a monoclinic crystal system with a space group of C2/c and Z = 8, and is stabilized by C12–H12⋯O1, and C8–H8A⋯O1 intramolecular hydrogen bonds. The presence of a distinctive azomethine C = N bond length N3-C12 of 1.283(3) Å, and 1640 cm−1 stretching vibration in the FT-IR spectrum are evidence of the formation of a Schiff base. The computational result indicates that the ionization energy (IE), and electron affinity (EA) values for the molecule are 4.025 and 2.110 eV, respectively. The positive value of EA suggests that the addition of an electron to the molecule would be an exothermic process. The evaluated energy is relatively low and is an expression of the ease of electron transfer from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO). Hirsfeld surface map over d n o r m and curvedness surface indicated the presence of π-π stacking while the shape factor index suggests donor and acceptor intermolecular C H—π. Analysis of Hirsfeld surfaces concerning the fingerprint indicated a minimal contribution from the d e − d i pair and reveals H—-H as a major contribution to the Hirsfeld surface. However, the molecular packing did not confirm H—-H as a significant contributor the packing. Docking calculations on the compound showed average theoretical binding energies toward aromatase (–5.99 ± 0.34 kcal/mol) and fibroblast growth factor receptor (FGFR) (–17.57 ± 6.85 kcal/mol), indicating binding interactions with both protein targets. [Display omitted] [ABSTRACT FROM AUTHOR]

• Computational study details the role of products of the reaction such as ethylene, as well as the solvent in determining the mechanism in iron-based hydroformylation catalysis. • Shows how iron complexes can be effective without the need for additional ligands. • Displays how β-hydride elimination is crucial to the success of the catalysis process. Iron is one of the most abundant transition metals in the earth's crust. It has attracted a lot of attention due to its low toxicity, bio-compatibility, and high natural abundance. Iron-catalyzed hydroamination, hydroalkoxylation, hydrocarboxylation, hydrosilylation, hydroboration, hydrophosphination, hydromagnesiation, and carbonylation reactions have therefore been developed over the past decades. However, despite many experimental and theoretical studies, a complete mechanistic understanding of iron-catalyzed hydrofunctionalisation at the molecular level has not yet been achieved. In this work, through density functional theory (DFT) calculations, we have shown the most feasible path for the hydroformylation of alkynes for an experimentally studied system. We have looked at the iron salt as a precatalyst without any external donor ligand, and the calculations revealed that hydrometalation followed by β-hydride elimination was favorable over the direct migration of the β-hydrogen to carbon. Furthermore, our calculations show that the solvent plays an important role in the hydromagnesiation reaction. Furthermore, we have employed an explicit solvent model, where the attachment of one molecule of solvent to the iron center was seen to stabilize the transition states significantly. [ABSTRACT FROM AUTHOR]

(a) The catalytic application of organolithium compounds is very limited due to their high reactivity and aggregation phenomena. However, the paradigm started to shift recently, when the groups of Okuda (J. Am. Chem. Soc. 2016, 138, 10790) and Mulvey (Chem. Eur. J., 2017, 23, 16853) reported the use of organolithium compounds for the hydroboration of aldehydes and ketones. Nonetheless, the catalytic use of organolithium compounds for reduction of more challenging and synthetically useful substrates such as carbodimides, esters etc. is deemed desirable. (b) Very recently, we have shown the use of organolithium compounds for the hydroboration of aldehydes and ketones (Chem. Commun. 2018, 54, 6843) as well as alkenes and alkynes (Chem. Commun. 2019, 55, 11711). Building upon our previous works, we demonstrate here catalytic hydroboration of ester to alcohol and carbodiimide to imine. (c) Prior to this work, there are few main-group catalysts reported for the hydroboration of carbodiimdies (See Chart 1 in the manuscript), but no well-defined group 1 complex as a single site catalyst has been used. The same is true for ester hydroboration. This is the first report of the catalytic hydroboration of esters and carbodiimides using single site catalyst based on a s -block element. (d) A thorough DFT studies were carried out to understand the mechanism of carbodiimide hydroboration. Selective and efficient hydroboration of esters and carbodiimides to alcohols and amines by two well-defined and readily accessible lithium complexes, 2,6-di-tert-butyl phenolate lithium (1a) and 1,1'-dilithioferrocene (1b) are described. A range of aliphatic, aromatic, and cyclic esters with various functional groups were selectively converted into the corresponding boronate esters. Similarly, the single hydroboration of carbodiimides with aliphatic and aromatic substituents on the nitrogen atoms was studied. A possible mechanistic pathway of the hydroboration of carbodiimides with HBpin has been proposed using NMR studies and DFT calculations. These reactions are convenient alternatives to stoichiometric hydride reduction or hydrogenation. The employing of lithium complexes is also significant, because of the need to find cheap and green alternatives to noble metal complexes. [Display omitted] We have demonstrated the use of simple and readily available lithium compounds, 2,6-di-tert-butyl phenolate lithium (1a) and 1,1'-dilithioferrocene (1b) as single site catalysts for hydroboration of diverse esters and carbodiimides in high yields and excellent functional group tolerance. DFT studies have been performed to understand the mechanism of carbodiimide hydroboration. [ABSTRACT FROM AUTHOR]